Bermudagrass Johnsongrass Medusahead Quackgrass Field Bindweed Hoary Cress Diffuse Knapweed Russian Knapweed Spotted Knapweed Squarrose Knapweed Purple Loosestrife Perennial Pepperweed Leafy Spurge Yellow Starthsitle Canada Thistle Musk Thistle Scotch Thistle Dyer's Woad Back to main weeds page   Purple Loosestrife Lythrum salicaria   Rosette Leaves are lance shaped with smooth margins up to five inches long. Adult Purple loosestrife is a semi-aquatic perennial growing six to eight feet tall. Flower There are five to seven petals on rose-purple flowers that appear in columns along the upper end of stems. Bloom is in midsummer. Weed Infestation Purple loosestrife is a European plant probably introduced to the United States as an ornamental. It reproduces by both seed and creeping rootstocks. Infestations can impede water flow and replace beneficial plants and thus displace wildlife. It can be found in shallow marshy wetland areas and ditches. Root Back to main weeds page   Buffalobur Common Burdock Camelthorn Goatsrue Jointed Goatgrass Poison Hemlock Black Henbane Houndstongue Blue-Flowering Lettuce Western Whorled Milkweed Silverleaf Nightshade Yellow Nutsedge Puncturevine Russian-Olive Saltcedar St. Johnswort Bull Thistle Dalmatian Toadflax Yellow Toadflax Velvetleaf